1. Field of Invention
The present invention relates to a tied down, in particular, to a rigid tie down in the field of mechanics.
2. Related Art
Goods usually desire to be bound during transportation by vehicles to prevent the goods falling off or colliding with each other to cause loss or damage during travel of the vehicles. Although cords are conventionally directly used to bind the goods, they are time and labor consuming and could hardly bind the goods tightly. The tie down is an advanced binding means, the use of which is very popular among drivers due to convenience and safety.
The conventional tie down is made of a support, a belt axis and a binding strap. The belt axis is connected to the support and rotatable. The binding strap is wound around the belt axis. A crowbar hole is set on the outer end of the belt axis beyond the support.
In order for the goods to be bound, the crowbar is inserted into the crowbar hole to turn the crowbar to drive the belt axis to rotate, thereby furling the binding strap, in which case the goods are bound tightly. However, since the tie down is fixed on the vehicle body and restricted to a certain position, the crowbar should be pulled out and inserted into another crowbar hole after the belt axis is driven to rotate by a certain angle through turning the crowbar during operation, and thus the belt axis could continue to rotate.
Meanwhile, the crowbar has to be repeatedly pulled out and inserted, bringing inconvenience in practical use. To this end, a control device for controlling the belt axis to rotate was designed. By using such a control device, some convenience is provided when the goods are bound, but the action is quite slow during untying the goods.
It could be understood that the current tie down is labor and time consuming during operation, and has a low binding efficiency or a low untying speed. Moreover, since the crowbar are continually pulled out and inserted, the finger(s) or other parts of the operator tend to be hurt.
To address the afore-mentioned problems, a Chinese patent document, the publication number of which is CN2846294Y, discloses a rapid-turn manual tie down device, comprising a reel axis, an end cap, a ratchet wheel means, and a retaining means. The ratchet wheel means is mounted at one end of the reel axis. The end cap is mounted on the other end of the reel axis via a retaining means. The retaining means could be formed by providing an internal ratchet wheel hole in the end cap and a pin hole at the belt axis in which a spring and a pin are provided. One end of the pin is pressed within the internal ratchet wheel hole. The end cap could displace the pin via the internal ratchet wheel hole, so as to drive the reel axis to tighten the binding strap; and the reel axis could not turn in a reverse direction with the action of the ratchet wheel means when the end cap reverses.
The rapid-turn manual tie down device mentioned above has a relatively complicated configuration and could only turn in one way with the ratchet wheel in cooperation with the pawl. In addition, the rapid-turn manual tie down device has low safety and reliability during operation. The binding strap of said device could not be loosened quickly, which impairs the efficiency thereof. Said device further occupies a larger space.